The total 2010 present value of electrical system costs varies by up to 12% across cases, but all forecasts are by nature wrong, and these estimates have substantial uncertainties. Reinventing Fire says that “choices between such figures should rest much less on costs, which are roughly similar and all uncertain, than on risks, whose nature, gravity, and management differ profoundly.” Choosing “Transform” means spending more money up front, but less on fuel in the future. It also means fewer vulnerable transmission lines and more rooftop solar-electric systems.